For the last few days, on my PC at work Internet Explorer 11 on Windows 7, IE crashes and reloads every time I change pages in the forum. Doesn't happen with Safari on my elderly MacBook at home nor on my iPhone 4s.

IE doesn't properly support HTML and related standards and never has really. It's a Microsoft bodge on top of Mosaic the original graphical browser. It is no longer really supported by MS who are now promoting EDGE under Windows 10, which may eventually work properly.

Dates seem about the same, my work computer did numerous updates around then, the time of the most recent ransom-ware scare. I'm not sure that I get quite that scary a message (IIRC it doesn't say malicious) but something along those lines.

Although after killing KB4022168, I then had to reinstall 6 'important updates'. They wouldn't install as a group, so I then had to install them individually and restart the computer each time. Finally all seems to be well though, so thanks again!

I also read that the Micro$oft Internet Explorer 'team' aren't bothering to sort out this sort of behaviour any more, concentrating their resources on Microsoft Edge instead.

And yes, I know that there's no problem when using Firefox etc. - but that doesn't absolve Micro$oft from fixing their own browser compatibility issues. Particularly when those arise from so-called 'updates and improvements' of their own making.